A large and intense cyclone produced widespread heavy snowfall and blizzard conditions across much of the Upper Midwest region on 11 December – 12 December 2010. AWIPS images of 4-km resolution GOES-3 6.5 Âµm “water vapor channel” data (above) showed the evolution of several important storm features, including a well defined dry slot, deformation zone, and Trough of Warm Air Aloft (TROWAL). The highest snowfall totals with this storm included 26.0 inches at Winona Dam, Minnesota and 23.0 inches at Osceola, Wisconsin.

During the afternoon hours on 12 December, 1-km resolution MODIS false-color Red/Green/Blue (RGB) images created using the 0.65 Âµm “visible channel” and the 2.1 Âµm near-IR “snow/ice channel” (below) displayed the extent of some of the resulting snow cover — snow on the ground showed up as varying shades of darker red, in contrast to supercooled water droplet clouds which were the brighter features on the image.